| Subject | Re: [RFC][PATCH 05/22] sched: SCHED_DEADLINE policy implementation | From | Peter Zijlstra <> | Date | Thu, 11 Nov 2010 15:17:03 +0100 |
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On Fri, 2010-10-29 at 08:30 +0200, Raistlin wrote: > +static void update_curr_dl(struct rq *rq) > +{ > + struct task_struct *curr = rq->curr; > + struct sched_dl_entity *dl_se = &curr->dl; > + u64 delta_exec; > + > + if (!dl_task(curr) || !on_dl_rq(dl_se)) > + return; > + > + delta_exec = rq->clock - curr->se.exec_start; > + if (unlikely((s64)delta_exec < 0)) > + delta_exec = 0; > + > + schedstat_set(curr->se.statistics.exec_max, > + max(curr->se.statistics.exec_max, delta_exec)); > + > + curr->se.sum_exec_runtime += delta_exec; > + account_group_exec_runtime(curr, delta_exec); > + > + curr->se.exec_start = rq->clock; > + cpuacct_charge(curr, delta_exec); > + > + dl_se->runtime -= delta_exec; > + if (dl_runtime_exceeded(rq, dl_se)) { > + __dequeue_task_dl(rq, curr, 0); > + if (likely(start_dl_timer(dl_se))) > + dl_se->dl_throttled = 1; > + else > + enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH); > + > + resched_task(curr); > + } > +}
So you keep the current task in the rb-tree? If you remove the current task from the tree you don't have to do the whole dequeue/enqueue thing. Then again, I guess it only really matters once you push the deadline, which shouldn't be that often.
Also, you might want to put a conditional around that resched, no point rescheduling if you're still the leftmost task.
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